@kezo sorry should have said it still starts around 126 used to be 141 but 8 miles uses the first 30
So given you have 126 miles to start with in minus conditions, give or take driving style etc suggests there is something not quite right. FWIW Vauxhahall state 128 so your not far off the ballpark with 126.
It needs to go back to the dealer to have a full battery condition check and any necessary reconditiong done. Its aso wise to keep Mb up dated on any outcomes along with any complaints you have.